JPH062798B2 - Light-transmissive epoxy resin composition and optical semiconductor device - Google Patents

Description

The present invention relates to a light-transmissive epoxy resin composition which is preferably used for encapsulating optical semiconductors such as LEDs and a cured product of the epoxy resin composition. The present invention relates to a semiconductor device.

2. Description of the Related Art Conventionally, in the field of optical semiconductor peripheral materials, acid anhydride-curable epoxy resin compositions have been used for sealing optical semiconductors such as LEDs because of their excellent transparency. It is often used. On the other hand, a block copolymer (silicone-based flexibility-imparting agent) of an aromatic polymer and an organopolysiloxane is added to a general epoxy resin composition to suppress the occurrence of cracks during curing, and It is practiced to prevent defects in elements and devices.

However, since the silicone-based flexibility-imparting agent has a poor compatibility with the epoxy resin and impairs the transparency of the epoxy resin, a carboxyl group-containing diene-based rubber is used as an epoxy resin for optical semiconductors, which is required to have higher transparency than before. Quality polymers, that is, butadiene-acrylonitrile copolymer containing a terminal carboxyl group and polybutadiene containing a terminal carboxyl group are blended as a flexibility-imparting agent to improve crack resistance. Rubbery polymers have a problem that they are inferior in heat resistance to silicone-based flexibility imparting agents.

Therefore, it has been desired to develop an epoxy resin composition that retains good transparency even when a silicone-based flexibility-imparting agent having excellent heat resistance is added.

The present invention has been made in view of the above circumstances, and a light transmission that gives a cured product having excellent heat resistance and crack resistance by blending a silicone-based flexibility-imparting agent, and also having excellent transparency and a high glass transition temperature. An epoxy semiconductor composition and an optical semiconductor device sealed with a cured product of the epoxy resin composition are provided.

Means and Actions for Solving the Problem The present inventor has conducted extensive studies in order to achieve the above object, and as a result, in a light-transmissive epoxy resin composition containing an epoxy resin and an acid anhydride curing agent. , Using triglycidyl isocyanurate or a mixture of triglycidyl isocyanurate and a bisphenol A type epoxy resin as an epoxy resin, and using an aromatic polymer and an organopolysiloxane having a silicon atom number within a specific range, that is, 40 or less. When the copolymer is blended, the alkenyl group of the alkenyl group-containing epoxy resin novolac resin and the following general formula (1) are used as the copolymer. (However, R is a lower alkyl group and / or a phenyl group, a
Of 0.02 to 0.2, b is a positive number of 1.8 to 2.2, and 1.82 ≦ a + b ≦ 2.4), which is an organopolysiloxane having 10 to 40 silicon atoms. ≡SiH
When a copolymer obtained by addition reaction with is blended, the copolymer has good compatibility with the epoxy resin, and heat resistance and crack resistance can be increased without impairing the transparency of the epoxy resin. The inventors have found what can be done and have completed the present invention.

Therefore, the present invention provides (A) triglycidyl isocyanurate or triglycidyl isocyanurate and bisphenol A type epoxy resin, (B) acid anhydride curing agent, (C) aromatic polymer and 40 or less silicon atoms. There is provided a light-transmissive epoxy resin composition containing the copolymer with the organopolysiloxane, and an optical semiconductor device sealed with a cured product of the epoxy resin composition.

Hereinafter, the present invention will be described in more detail.

The composition of the present invention comprises an epoxy resin, an acid anhydride type curing agent and a silicone type copolymer.

Here, as the epoxy resin, triglycidyl isocyanurate is used, but more preferably, a mixture of triglycidyl isocyanurate and bisphenol A type epoxy resin is used. By using a mixture of triglycidyl isocyanurate and a bisphenol A type epoxy resin, excellent transparency, a high glass transition temperature and a low stress property are better imparted.

Here, as triglycidyl isocyanurate, for example, trade name TEPIC-H (epoxy equivalent 99, melting point 15
5 ° C., manufactured by Nissan Chemical Co., Ltd.).

As the bisphenol A type epoxy resin, for example, trade name Epicoat 1001 (epoxy equivalent 470, melting point 65 ° C., manufactured by Yuka Shell Epoxy Co., Ltd.), trade name Epicoat 1055 (epoxy equivalent 850, melting point 95 ° C., Yuka Shell Epoxy Co., Ltd.) Made), trade name Epicoat 1004 (epoxy equivalent 950, melting point 100 ° C., manufactured by Yuka Shell Epoxy Co., Ltd.), trade name Epicoat 1007 (epoxy equivalent 200)
0, melting point 130 ° C., manufactured by Yuka Shell Epoxy Co., Ltd., trade name Epiclon 1050 (epoxy equivalent 450, melting point 65)
℃, manufactured by Dainippon Ink and Chemicals, Inc., trade name Epicron 405
0 (epoxy equivalent 950, melting point 100 ° C, manufactured by Dainippon Ink and Chemicals), trade name DER661 (epoxy equivalent 45)
0, melting point 70 ° C., Dow Chemical Co., Ltd.), DER664
(Epoxy equivalent 925, melting point 100 ° C., Dow Chemical Co., Ltd.), trade name DER667 (epoxy equivalent 1800, melting point 120 ° C., Dow Chemical Co., Ltd.), etc., and one of these may be used alone or in combination of two or more. Can be used.

The ratio of the triglycidyl isocyanurate to the bisphenol A type epoxy resin used is 1 in weight ratio.
It is preferably 00:00 to 2000, particularly preferably 100: 0 to 850.

As the acid anhydride-based curing agent used in the composition of the present invention,
Any of those usually used for curing epoxy resins can be used, for example, phthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, anhydrous Pyromellitic acid, benzophenone tetracarboxylic acid anhydride, etc. are mentioned, and these 1 type can be used individually or in combination of 2 or more types. The acid anhydride curing agent is preferably added in an amount of 25 to 160 parts, particularly 33 to 160 parts, per 100 parts (parts by weight, the same hereinafter) of the epoxy resin.

In addition to the epoxy resin and the acid anhydride-based curing agent described above, the composition of the present invention may optionally contain a curing accelerator in a conventional range.

Examples of the curing accelerator include 2-methylimidazole,
Imidazole compounds such as 2-phennylimidazole, 4-ethyl-2-methylimidazole, 4-methyl-2-ethylimidazole, triphenylphosphine, tricyclohexylphosphine, tributylphosphine,
Organic phosphine compounds such as methyldiphenylphosphine, 1,8-diaza-bicyclo (5.4.0) undecene-7 or its phenol salt, 2-ethylhexane salt,
Examples thereof include oleate and acidic carbonate.

In addition to the above components, the composition of the present invention contains a copolymer of an aromatic polymer and an organopolysiloxane having 40 or less silicon atoms.

Here, as the aromatic polymer, epoxy novolac resin, phenol novolac resin, and cresol novolac resin are preferable. As the organopolysiloxane, those having functional groups capable of reacting with the groups in these novolak resins and having 40 or less silicon atoms are used.
Specifically, as the type of reaction, for example, a reaction of an organopolysiloxane containing an amino group with an epoxy novolac resin, a reaction of an organopolysiloxane containing an epoxy group with a phenol novolac resin, an epoxy novolak containing an alkenyl group. Hydrosilyl group for resin and phenol novolac resin Examples of the reaction include a reaction of an organopolysiloxane containing a. Of these reactions, from the viewpoints of transparency and imparting stress-reducing properties, an epoxynovolak resin containing an alkenyl group and an organopolysiloxane containing a hydrosilyl group are used. Copolymers by reaction are most suitable.

In this case, the alkenyl group-containing epoxy novolac resin is obtained by a method such as epoxidizing the alkenyl group-containing phenol novolac resin with epichlorohydrin, or partially reacting the epoxy novolac resin with 2-allylphenol, allyl alcohol, or the like. And specifically, the following formulas (2) to (4) formula (2) Formula (3) Formula (4) (However, in the above formulas (2) to (4), p and q are usually 1 ≦ p.
≦ 10, 1 ≦ q ≦ 3, which represents a positive number).

On the other hand, the organopolysiloxane containing a hydrosilyl group is represented by the following general formula (1) (However, R is a lower alkyl group and / or a phenyl group, a
Is an integer of 0.02 to 0.2, b is a positive number of 1.8 to 2.2, and 1.82 ≦ a + b ≦ 2.4). It is suitable. The organopolysiloxane represented by the above formula (1) may be one having at least one ≡SiH group in one molecule, and particularly, both-terminal hydrogen dimethyl polysiloxane and both-terminal hydrogen methylphenyl polysiloxane are preferable. It is suitable. Specifically, the following formula (5)-
(7) Formula (5) Formula (6) Formula (7) Examples include organopolysiloxanes represented by
It is not limited to these.

The organopolysiloxane used in the synthesis of the silicone-based copolymer of the present invention has 40 or less silicon atoms,
It is necessary to be preferably in the range of 10 to 40,
A silicone-based copolymer using an organopolysiloxane having less than 10 silicon atoms may not be able to impart sufficient flexibility to an epoxy resin and may be unable to impart a high glass transition temperature. On the other hand, when the number of silicon atoms exceeds 40, the silicone-based copolymer using the organopolysiloxane becomes poor in compatibility with the epoxy resin, and sufficient transparency and light transmission cannot be obtained. Further, in order to improve the compatibility of the organopolysiloxane with the epoxy resin and to obtain further transparency and light transmittance, the side chain of the polysiloxane, that is, R in the above formula (1), is in the range of 30 mol% or less. It is preferable to introduce a phenyl group.

The above-mentioned alkenyl group-containing epoxy novolac resin and the organopolysiloxane having the ≡SiH group represented by the above formula (1) are obtained by adding an alkenyl group and an ≡SiH group to a known addition catalyst, for example, a platinum system such as chloroplatinic acid. It can be obtained by heating reaction in the presence of a catalyst.

In addition to the above-mentioned components, it is preferable to add a discoloration inhibitor to the composition of the present invention.

Examples of the discoloration preventing agent include reducing organic phosphite compounds such as triphenylphosphite, tridecylphosphite, and diphenylmonodecylphosphite, as well as 9,10-dihydro-9-oxa-10-phosphaphenanthrene. -10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, and further 2,6-di-t-butyl-4-methylphenol (BHT), 2,4. Examples thereof include hindered phenol compounds such as 6-tricyclohexylphenol and 2,4,6-tribenzylphenol.

In addition, the composition of the present invention further includes various additives as required depending on the purpose and application, such as a silane coupling agent, a wax agent, a releasing agent such as a fatty acid such as stearic acid and a metal salt thereof, a dye, Other additives may be blended.

The silane coupling agent may be represented by the following formula in order to impart hydrophobicity or adhesion to the composition of the present invention. CH ₃ (CH ₂ ) _n CH ₂ Si (OCH ₃ ) ₃ n = 1 to 10 CH ₃ Si (OCH ₃ ) ₃ HSCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ NH ₂ CH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ NH ₂ CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ and other silane coupling agents, alone or in combination of two or more. It is desirable to mix them.

In the case of producing the composition of the present invention, predetermined amounts of the above-mentioned components are uniformly stirred and mixed, and kneaded with a kneader, roll, extruder or the like preheated to 70 to 95 ° C, cooled, pulverized, etc. Can be obtained by In addition,
There is no particular limitation on the order of mixing the components.

The composition of the present invention can be used for encapsulating an optical semiconductor device such as an LED by employing a conventionally used molding method such as transfer molding, injection molding, or casting method. In this case, the molding temperature of the epoxy resin composition is 140 to 160 ° C., and the post cure is 140 to 1
It is preferable to carry out at 60 ° C. for 2 to 16 hours. When the composition of the present invention is used, in order to exhibit high transparency, it is desirable to sufficiently melt-mix the epoxy resin, the acid anhydride curing agent, the silicone copolymer and the like before using them. .

As described above, the light-transmitting epoxy resin composition of the present invention is excellent in heat resistance and crack resistance, and its cured product has excellent transparency and a high glass transition temperature. An optical semiconductor such as an LED, which is sealed with the cured product of the composition of the present invention, can retain excellent properties. In addition, the composition of the present invention can be mass-produced because it can be pressure-molded such as transfer molding.

Hereinafter, the present invention will be specifically described by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples. Before describing the examples and comparative examples, examples of producing the copolymer used in the examples will be described.

[Production example]

A four-necked flask with an internal volume of 1 equipped with a reflux condenser, a thermometer, a stirrer and a dropping funnel has a softening point of 8
300 g of an epoxidized phenol novolac resin (epoxy equivalent 195) at 0 ° C. was added, and while stirring at a temperature of 110 ° C., 32 g of 2-allylphenol and 1 of tributylamine were added.
The mixture with g was added dropwise at a dropping time of 10 minutes, and the temperature was adjusted to 1
Stirring was continued for 2 hours at 10 ° C. Unreacted 2-allylphenol and tributylamine were distilled off from the obtained contents under reduced pressure to obtain an allyl group-containing epoxy resin (allyl equivalent 1490, epoxy equivalent 235).

Then, in a four-necked flask similar to the above, 120 g of the allyl group-containing epoxy resin obtained by the above method, 100 g of methyl isobutyl ketone, 200 g of toluene, and 2% platinum concentration of 2
-Add 0.04 g of ethylhexanol-modified chloroplatinic acid solution, perform azeotropic dehydration for 1 hour, add 80 g of organopolysiloxane shown in Table 1 at a reflux temperature at a dropping time of 30 minutes, and further at the same temperature. After reacting by stirring for 4 hours at room temperature, the obtained contents were washed with water, and the solvent was distilled off under reduced pressure to obtain reaction products (copolymers I, II, III) shown in Table 1. It was

Compound A Compound B Compound C [Examples and Comparative Examples] Bisphenol A type epoxy resin having an epoxy equivalent of 850 (Epicoat 1055K manufactured by Yuka Shell Epoxy Co., Ltd.), triglycidyl isocyanurate having an epoxy equivalent of 99 (TEPIC-H manufactured by Nissan Kagaku Co.) hexahydrophthalic anhydride (new Rikacid HH manufactured by Nippon Rika), the copolymer obtained in the above production example, 2-phenylimidazole, the following formula: The 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (Sanko Chemical Co., Ltd., product name HCA) and a coupling agent represented by
An epoxy resin composition was prepared by using the compounding amounts shown in the table.

The following tests were conducted on these epoxy resin compositions.

5 × 5 under the conditions of expansion coefficient, glass transition temperature 150 ℃, 20kg / cm ² , molding time 7 minutes
A test piece of 15 mm × 15 mm was molded and post-cured at 150 ° C for 4 hours.
The temperature was raised at a rate of ° C and the measurement was performed.

Mold a test piece with a light transmittance of 10 x 50 x 1 mm at 150 ° C for 7 minutes and
The light transmittance at 700 nm was measured by using an absorptiometer for the post-cured product at 50 ° C. for 4 hours.

Crack resistance 9.0 × 4.5 × 0.5 mm silicon chip with a size of 14 mm is adhered to a 14 PIN-IC frame (42 alloy), and an epoxy resin composition is molded at 150 ° C. for 7 minutes.
After post-curing at 50 ° C for 4 hours, -50 ° C x 30
Min-150 ℃ × 30 minutes repeated heat cycle,
The resin crack occurrence rate after 200 cycles was measured.

Hygroscopicity The same 5 × 5 × 15 mm test piece used for the measurement of the expansion coefficient was used, and the measurement was performed after leaving it at 85 ° C./85% RH for 100 hours.

Adhesion: Bonding a silicon chip with a size of 9.0 × 4.5 × 0.5 mm to a 14PIN-IC frame (42 alloy), molding this with an epoxy resin composition at 150 ° C. × 7 minutes, and then 150 ° C. After post-cure for 4 hours at 215
The adhesion at the interface between the silicon chip and the resin after the treatment with VPS at 30 ° C. for 30 seconds was measured with an ultrasonic flaw detector.

The hygroscopicity and the adhesive strength were evaluated in three grades of ⊚: excellent ∘: good ×: bad.

The results are also shown in Table 1.

From the results shown in Table 1, when the copolymer is not blended (Comparative Examples 1 and 2), the transparency of the cured product is good, but the crack resistance, hygroscopicity, adhesion are poor, and the degree of polymerization is When a copolymer containing 80 or more organopolysiloxanes is blended (Comparative Example 3), the cured product has almost no transparency, and also has poor hygroscopicity and adhesion. On the other hand, it is recognized that the composition of the present invention has good transparency and is excellent in various properties such as crack resistance, hygroscopicity and adhesion.

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Claims (2)

[Claims] 1. (A) Triglycidyl isocyanurate or triglycidyl isocyanurate and bisphenol A
-Type epoxy resin, (B) acid anhydride curing agent, (C) light-transmitting epoxy resin composition containing a copolymer of an aromatic polymer and an organopolysiloxane having 40 or less silicon atoms . 2. An optical semiconductor device encapsulated with the cured product of the composition according to claim 1.